The present invention relates to an electrical connector and more specifically to a connector which has a so-called "dead front" construction.
Electrical connectors which have dead front construction have no exposed parts to which wires are attached other than the electric blades which are to receive power from a receptacle or the openings to the contacts of a receptacle itself.
The concept of the use of a dead front type of construction is that it increases the safety associated with the use of connectors including both plugs for receiving electric power and receptacles for delivering electric power to plugs. In prior art devices there was access to the screws to which wires were connected through the face of the plug having the power blades extending therefrom. For many such prior art plugs there were various forms of covers that were to be placed over the face and to have the blades extending through the cover, but these covers were not always employed by the users of the plug so that when the cover was absent the screws to which wires were attached were accessible from the face. Further, any wire attached to the screws which became loose or unravelled could extend out from the plug to make contact with a user or with a metal plate into which the plug was inserted.
In recent times the standard making organizations of this country and particularly the Underwriters Laboratories has studied this problem and has determined that connectors, and particularly plugs, should have a dead front construction. The mandating of the use of dead front plugs by UL was the subject of a standard and this standard is now in force.
One patent which describes a dead front plug construction is the Hoffmann U.S. Pat. No. 4,010,999. The construction of the plug of this patent is of the so-called "valise" type. Such a valise type construction was known prior to the Hoffmann patent and was in fact shown and described in British Pat. No. 676,144.